(a) Field of the Invention
The present invention relates to a liquid developer for electrophotography used for developing an electrostatic latent image.
(b) Description of the Prior Art
A liquid developer used for developing an electrostatic latent image formed by electrophotographic method, electrostatic recording method, electrostatic printing method or the like, is well known. This liquid developer generally comprises a dispersion of fine toner particles composed of coloring agents and resins as the main components in a highly insulating aliphatic hydrocarbon and/or halogenated hydrocarbon having a low dielectric constant as a carrier liquid.
Toner particles of the conventional liquid developer has a mean particle size of not larger than 1 .mu.m and a particle size distribution having only one peak. It was generally considered that toner particles having a smaller particle size provided better resolving power. However, developed image density provided by the toner having the above mentioned average particle size and particle size distribution was limited.
Japanese Patent Laid Open No. 59-26743 discloses a developer which provides highly improved density of developed image. This developer is characterized by the toner particles having two particle size distribution peaks in the range of 0.01 .mu.m and 1 to 30 .mu.m. However, this developer disclosed in the above Japanese Patent Laid Open No. 59-26743 was still unsatisfactory in respect to resolving power and fixativity immediately after copying.